White-nose syndrome, a disease deadly to bats, has been detected in both Acadia and Great Smoky Mountains national parks.

Biologists estimate that the disease has killed nearly 7 million bats in North America since it was discovered in a cave in upstate New York in 2006. While it's not considered a health threat to humans, white-nose syndrome is deadly to bats, and there are fears that entire species could be eradicated by it.

White-nose syndrome is caused by the fungus Geomyces destructans. The fungus thrives in cold and humid conditions typical of those found in caves and mines in which many bat species hibernate.

Bats with WNS appear to use up their precious fat reserves too quickly to stay in hibernation through the winter. The disease got its name from the white fungal growth that can be seen around the muzzles, ears, and wing membranes of affected bats, typically during their hibernation.

As the disease spreads, its impacts could ripple through ecosystems. Not only are bats efficient predators when it comes to insect control -- some bats can eat up to 2,000 mosquito-sized insects in a single night -- but they in turn are prey for hawks, owls, and skunks, just to name some predators.

“Learning that white-nose syndrome has been documented in Acadia and Hancock County bats is disappointing,” said Acadia Superintendent Sheridan Steele in a prepared statement Tuesday. "The National Park Service is working closely with Maine Department of Inland Fisheries and Wildlife, the U.S. Fish and Wildlife Service, and the U.S. Geological Survey National Wildlife Health Center to implement protective protocols to limit the spread of this fungus in Maine's bat populations.

"Bats are important because they play a critical role in maintaining healthy ecosystems and are tremendously important in managing mosquitoes and other biting insects. Losing even a small percentage of Maine's bats could have a devastating effect on one of nature’s ecological controls of forest and wetland insects.

As a result of the disease, "We are more likely to see bats out during the daytime and during seasons when they are not normally active in Maine," added the superintendent. "We discourage anyone from handling or disturbing roosting bats, as these actions can only further stress individuals and the remaining populations."

At Great Smoky, where human access to caves was halted in April 2009 in an effort to stop the spread of WNS, biologists said that both a tricolored bat and a little brown bat found in a park cave tested positive for the disease. This discovery transitions the park from only finding evidence of the fungus that causes WNS in a cave to now finding animals actively affected by the disease, officials said Tuesday.

"While the confirmation of WNS in the park is not a surprise it is still a sad day for the resource," said Great Smoky Superintendent Dale Ditmanson. "By continuing to monitor bat populations in our caves and forests we hope to minimize WNS affecting other bat habitats outside of our boundaries"

White-nose syndrome has previously been documented at other Park Service units, including Delaware Water Gap National Recreation Area in New Jersey, in 2009, and Russell Cave National Monument in Alabama, where the disease was confirmed just last week, according to the Center for Biological Diversity.

“Discovery of white-nose syndrome at two of our leading national parks is particularly troubling because of the vital role these parks play in safeguarding wildlife and plant populations,” said Mollie Matteson, a bat specialist at the Center for Biological Diversity.

Bruce Connery, a wildlife biologist at Acadia, said humans possibly could transport WNS fungal spores on clothing and gear. “The fungus cannot be killed simply by washing clothing and equipment," he said.

"Coastal environments were not thought to have bats in winter and seemed insulated from areas where white-nose syndrome had been found," Mr. Connery added. "This year we have been getting reports about bats being active throughout the winter. We tested two bats found in the park this winter and discovered that they had the disease.

"Our biggest concern is public response to this announcement and being able to clear up the many misconceptions about bats. Bats are highly valuable in the ecological scheme of the park and only if visitors and neighbors work cooperatively with all conservation efforts will the remaining bats be protected in Maine and throughout the Northeast," he said.

White-nose syndrome is now confirmed in 17 states and suspected in another three; it is also confirmed in four Canadian provinces, the Center reported.

“This disease is filling in the map like a horrible paint-by-numbers project,” said Ms. Matteson. “The rapid spread of white-nose syndrome in Indiana is especially troubling, because that state hosts the majority of hibernating Indiana bats in the country.”

The Indiana bat is a federally listed endangered species, and has declined by 70 percent in the northeastern portion of its range, according to the organization. White-nose syndrome first arrived in the Midwest last winter, and has been showing up in numerous new counties in Ohio, Kentucky and Indiana this year.

Six species of bat have been lethally affected by white-nose syndrome to date. Another three species, including the federally endangered gray bat, have been documented with the white-nose fungus on them. Biologists are deeply concerned that the bat disease may soon show up in the American West; the fungus was found on a nonsymptomatic bat in a cave in western Oklahoma in 2010.

Scientists have determined that the disease is caused by a previously unknown fungus, likely introduced by cave visitors from Europe. In Europe the fungus has been discovered on bats in several countries, but it appears to do little to no harm to them. Unfortunately, that's not the case in U.S. bat colonies.

“Left unchecked, this disease could wipe out several species of bats,” said Ms. Matteson. “This would not only be a tragedy for those species but would have ripple effects on us — because we depend on the insect-control services bats provide by eating thousands of tons of insects every year, including those that attack farmers’ crops.”

While Mammoth Cave National Park leads about 400,000 visitors a year through about 10 miles of the nearly 400 miles of passages interlaced within the park's massive cave systems, it still has been free of the disease. Officials in 2010 began developing protocols for dealing with WNS, both to keep it from entering the cave system or being carried out of the system on visitors' feet or clothing if it ever does show up there.

Those protocols range from addressing the issue on the park's website to discussing it with visitors before they go underground on cave tours. About 15 minutes before each tour leaves, an announcement concerning WNS is made. In it visitors are asked if they have been in a cave in the past five years and, if so, are they wearing any footwear or clothing, or carrying any items, such as a camera, that they had with them on those previous caving experiences.

If visitors are wearing footwear that has been in another cave, the shoes are treated with a concentration of an industrially concentrated solution of Lysol that testing at Northern Kentucky University has shown to be effective at killing the fungus. In the case of items such as jewelry or cameras, Lysol wipes are used to clean the items. Jewelry also can be placed in Ziplock baggies.